Threaded pipe unions, which are often called “hammer unions,” generally include a male sub, a threaded wing nut, and a female sub. These hammer unions often form a part of a system that is used to facilitate oil and gas exploration and production operations. One example is a hydraulic fracturing (or “frac”) system, which pumps fluid to a wellhead for the purpose of propagating factures in a formation through which a wellbore extends, the wellhead being the surface termination of the wellbore. When used in a frac system, the threaded wing nut may be subjected to high stress, which may result in cracks propagating near a threaded portion of the wing nut. These cracks often lead to failure of the hammer union. Therefore, what is needed is an apparatus that addresses one or more of the foregoing issues or other(s).